package collection;

import java.util.*;

public class TestMain{
    public static void main(String[] args) {
//        String[] a={"1,2,0,8,2","12313","sdwda"};
//        for(String n:a){
//            System.out.println(n);
//        }
       // 集合
        Set s1 = new HashSet();
        s1.add("sda");
        s1.add("1212");
        s1.add(1243);
        s1.add('s');
        s1.add(null);
        Set s2 = new TreeSet();
        Set s3 = new LinkedHashSet();

        List l1 = new ArrayList();
        List l2 = new LinkedList();

        Map m1 = new HashMap();
        m1.put(0,123);
        m1.put(1,46);
        m1.put(2,1887);
        m1.put(3,78654);
        m1.put(4,877);
        Map m2 = new TreeMap();
        Map m3 = new LinkedHashMap();

        Iterator iter= s1.iterator();
        if(iter.hasNext()){
            System.out.println(iter.next());
        }
    }
}
